GATE Overflow for GATE BT - Questions without answers in Genetics and Evolutionary Biology

GATE BT 2026 | Question: 28

Mon, 23 Feb 2026 14:21:23 +0000

Match the genetic disorders in Column $\text{I}$ to the corresponding underlying cause in Column $\text{II}$

\[
\begin{array}{|l|l|}
\hline
\text{Column I} & \text{Column II} \\
\hline
\text{P. Klinefelter Syndrome} & 1.\ \text{X-chromosome insufficiency} \\
\hline
\text{Q. Turner syndrome} & 2.\ \text{DNA helicase mutations} \\
\hline
\text{R. Bloom syndrome} & 3.\ \text{Nucleotide excision repair defects} \\
\hline
\text{S. Xeroderma pigmentosum} & 4.\ \text{Extra X chromosome(s) in a male} \\
\hline
\end{array}
\]

$\text{P-1; Q-3; R-4; S-2}$
$\text{P-4; Q-1; R-2; S-3}$
$\text{P-4; Q-2; R-3; S-1}$
$\text{P-3; Q-2; R-4; S-1}$

GATE BT 2026 | Question: 54

Mon, 23 Feb 2026 14:20:25 +0000

A disease-associated allele shows $\text{X}$-linked recessive inheritance. If the mother is a carrier of the disease, the father is genetically normal and the child born is a son, then the probability that he is born with the disease is $\_\_\_\_$ (rounded off to one decimal place)

GATE BT 2025 | Question: 43

Thu, 06 Mar 2025 17:04:44 +0000

The blood group of the mother is $\mathrm{A}^{+}$and that of the father is $\mathrm{AB}^{+}$. Which of the following statements is/are correct?

Probability of the offspring with $\mathrm{A}^{+}$blood group is $0.5$
Probability of the offspring with $\mathrm{AB}^{+}$blood group is $0.125$
Probability of the offspring with $\mathrm{B}^{+}$blood group is $0.125$
Probability of the offspring with $\mathrm{O}^{+}$blood group is $0.375$

GATE BT 2024 | Question: 6

Mon, 25 Mar 2024 19:16:30 +0000

Mendel's 'law of segregation' applies to the segregation of $\_\_\_\_\_\_\_\_$ during gamete formation.

mitochondrial genes
alleles of a gene
linked genes on the same chromosome
unlinked genes on the same chromosome

GATE BT 2024 | Question: 33

Mon, 25 Mar 2024 19:16:16 +0000

The evolution of wings in bats and insects is an example of $\_\_\_\_\_\_\_$ evolution.

convergent
divergent
neutral
parallel

GATE BT 2023 | Question: 4

Sun, 21 May 2023 02:58:48 +0000

Determine the correctness or otherwise of the following Assertion $[\text{a}]$ and the Reason $\text{[r]}$.

Assertion $\text{[a]}$: Chromosome mutations can change the structure of chromosomes.

Reason $\text{[r]}$ : All chromosome mutations arise due to nondisjunction of chromosomes during mitosis or meiosis.

Both $\text{[a]}$ and $\text{[r]}$ are false
$\text{[a]}$ is true but $\text{[r]}$ is false
Both $\text{[a]}$ and $[\mathrm{r}]$ are true and $[\mathrm{r}]$ is the correct reason for $\text{[a]}$
Both $\text{[a]}$ and $[\mathrm{r}]$ are true but $[\mathrm{r}]$ is not the correct reason for $\text{[a]}$

GATE BT 2023 | Question: 20

Sun, 21 May 2023 02:58:35 +0000

Fabry disease in humans is a X-linked disease. The probability (in percentage) for a phenotypically normal father and a carrier mother to have a son with Fabry disease is _________.

GATE BT 2022 | Question: 17

Sun, 20 Mar 2022 16:16:28 +0000

Assuming independent assortment and no recombination, the number of different combinations of maternal and paternal chromosomes in gametes of an organism with a diploid number of $12$ is __________.

GATE BT 2022 | Question: 26

Sun, 20 Mar 2022 16:16:27 +0000

Which of the following conditions will contribute to the stability of a gene pool in a natural population?

Large population
No net mutation
Non-random mating
No selection

$\text{P}$ Only
$\text{P}$ and $\text{Q}$ Only
$\text{P}$ and $\text{R}$ Only
$\text{P},$ $\text{Q}$ and $\text{S}$ Only

GATE BT 2021 | Question: 6

Mon, 01 Mar 2021 03:19:51 +0000

The order of genes present in a chromosome is as follows

Which one of the following rearrangements represents a paracentric inversion?

GATE BT 2021 | Question: 39

Mon, 01 Mar 2021 03:19:47 +0000

In a Mendel’s dilhybrid experiment, a homozygous pea plant with round yellow seeds was crossed with a homozygous plant with wrinkled green seeds.

$F_1$ intercross produced $560 \: F_2$ progency. The number of $F_2$ progency having both dominant traits (round and yellow) is ____________

GATE BT 2021 | Question: 48

Mon, 01 Mar 2021 03:19:46 +0000

In a random mating population, $Y$ and $y$ are dominant and recessive alleles, respectively. If the frequency of $Y$ allele in both sperm and egg is $0.70$, then the frequency $Y/y$ heterozygotes (rounded off to two decimal places) is ___________.

GATE2019: 47

Tue, 03 Nov 2020 12:02:06 +0000

In pea plants, purple color of flowers is determined by the dominant allele while white color is determined by the recessive allele. A genetic cross between two purple flower bearing plants results in an offspring with white flowers. The probability that the third offspring from these parents will have purple flowers is ____________ (rounded off to $2$ decimal places).

GATE2020: 31

Tue, 03 Nov 2020 11:16:27 +0000

In tomato plant, red ($R$) is dominant over yellow ($r$) for fruit color and purple ($P$) is dominant over green ($p$) for stem color. Fruit color and stem color assort independently. The number of progeny plants of different fruit/stem colors obtained from a mating are as follows:

Red fruit, purple stem – $145$

Red fruit, green stem – $184$

Yellow fruit, purple stem – $66$

Yellow fruit, green stem – $47$

What are the genotypes of the parent plants in this mating?

$RrPp \times Rrpp$
$RrPp \times RrPp$
$RRPP \times rrpp$
$RrPP \times Rrpp$

GATE2016-33

Mon, 26 Mar 2018 16:59:49 +0000

Match the type of chromosomal inheritance (Column-I) with the corresponding genetic disease or trait (Column-II).

$\begin{array}{|l|l|l|l|} \hline & \textbf{Column-I} & & \textbf{Column-II} \\ \hline P. & \text{Autosomal recessive inheritance} & 1. & \text{Huntington disease} \\ \hline Q. & \text{Autosomal dominant inheritance} & 2. & \text{Hairy ears} \\ \hline R. & \text{X-linked inheritance} & 3. & \text{Cystic fibrosis} \\ \hline S. & \text{Y-linked inheritance} & 4. & \text{Hemophilia} \\ \hline \end{array}$

$\text{P-1, Q-4, R-3, S-2}$
$\text{P-4, Q-3, R-2, S-1}$
$\text{P-3, Q-1, R-4, S-2}$
$\text{P-4, Q-2, R-3, S-1}$

GATE2016-34

Mon, 26 Mar 2018 16:59:48 +0000

A crossing was performed between the genotypes $\textit{DdEeFfgg}$ and $\textit{ddEeFfGg}$. Assuming that the allelic pairs of all genes assort independently, the proportion of progeny having the genotype $\textit{ddeeffgg}$ is expected to be _______ $\%$

GATE BT 2017 | Question: 45

Mon, 26 Mar 2018 16:43:15 +0000

A pedigree of an inheritable disease is shown below.

This inheritable disease is

$X$-linked dominant
$X$-linked recessive or Y-linked
only $Y$-linked
only $X$-linked recessive

GATE BT 2015 | Question: 36

Mon, 26 Mar 2018 15:10:46 +0000

An isolated population on an island has the following genotypic frequencies: $$\begin{array}{|c|c|c|c|} \hline \textrm{Genotype} & AA & Aa & aa \\ \hline \textrm{Frequency} & 0.3 & 0.4 & 0.3 \\ \hline \end{array}$$ Assuming that there are only two alleles ($A$ and $a$) for the gene, the genotypic frequency of $AA$ in the next generation will be __________

GATE2014-35

Sun, 25 Mar 2018 23:27:37 +0000

In a relatively large but finite and closed population of sexually reproducing diploid organisms, the frequency of homozygous genotype PP changes from 0.40 to 0.50 and that of pp changes om 0.40 to 0.41 in a span of 10 generations. Which of the following is the most likely cause for the above change in frequency of the PP genotype?

Non-random mating
Random genetic drift
Selection
Combination of non-random mating and random genetic drift

GATE2014-37

Sun, 25 Mar 2018 23:27:37 +0000

Consider a population of $10,000$ individuals, of which $2500$ are homozygotes (PP) and $3000$ are heterozygotes (Pp) genotype. The frequency of allele p in the population is_________.

GATE2014-47

Sun, 25 Mar 2018 23:27:35 +0000

In a genetic cross between the genotypes $WWXX$ and $\text{wwxx}$, the following phenotypic distributions were observed among the $F_2$ progeny: $\text{WX, 562; wx, 158; WX, 38; and wX, 42}$. Likewise, a cross between $XXYY$ and $\text{xxyy}$ yielded the following results: $\text{XY, 675; xy, 175; Xy, 72; and xY, 78.}$ Similarly, a cross between $WWYY$ and $\text{wwyy}$ yielded: $\text{WY, 292; wy, 88; Wy, 12; and wY, 8.}$ In all the genotypes, capital letters denote the dominant allele. Assume that the F1 progeny were self-fertilized in all three crosses. Also, double cross-over does not occur in this species. Which of the following is correct?

Relative position: $\text{W-X-Y}$ Distances: $\text{W-X = 5}$ map units, $\text{X-Y = 17}$ map units
Relative position: $\text{X-Y-W}$ Distances: $\text{X-Y = 15}$ map units, $\text{Y-W = 11}$ map units
Relative position: $\text{Y-W-X}$ Distances: $\text{Y-W = 5}$ map units, $\text{W -X = 11}$ map units
Relative position: $\text{X-W-Y}$ Distances: $\text{X-W = 5}$ map units, $\text{W-Y = 10}$ map units

GATE2014-53

Sun, 25 Mar 2018 23:27:34 +0000

A dioecious plant has $XX$ sexual genotype for female and $XY$ for male. After double fertilization, what would be the genotype of the embryos and endosperms?

$100\%$ ovules will have $XXX$ endosperm and $XX$ embryo
$100\%$ ovules will have $XXY$ endosperm and $XY$ embryo
$50\%$ ovules will have $XYY$ endosperm and $XY$ embryo, while other $50\%$ will have $XXY$ endosperm and $YY$ embryo
$50\%$ ovules will have $XXX$ endosperm and $XX$ embryo, while the other $50\%$ will have $XXY$ endosperm and $XY$ embryo

GATE BT 2013 | Question: 44

Sun, 25 Mar 2018 20:06:02 +0000

In a genetic study, $80$ people were found to have alleles for polydactyly. Only $36$ of them were polydactylous. What is the extent of penetrance percentage? _____________

GATE BT 2012 | Question: 31

Sun, 25 Mar 2018 08:38:45 +0000

Match the terms in $\textbf{Group I}$ with the ploidy in $\textbf{Group II}$.

$\begin{array}{|C|l|C|l|} \hline &\textbf{Group I} & {} &\textbf{Group II} \\\hline P. &\text{Disome} & 1. &\text{2n+1} \\\hline Q. &\text{Monosome} & 2. &\text{2n-1} \\\hline R. &\text{Nullisome} & 3. &\text{n-1} \\\hline S. &\text{Trisome} & 4. &\text{n+1} \\\hline\end{array}$

$\text{P-4,Q-2, R-3, S-1}$
$\text{P-4, Q-3, R-1, S-2}$
$\text{P-2, Q-3, R-4, S-1}$
$\text{P-l, Q-4, R-3, S-2}$

GATE BT 2012 | Question: 14

Sun, 25 Mar 2018 08:38:43 +0000

The direction of shell coiling in the snail $\text{Limnaea peregra}$ is a classic example of

chromosomal inheritance
extra-chromosomal inheritance
chromosomal translocation
homologous recombination