Mechanical barriers provide a first line of defence against insect pests and pathogens, these mechanical barriers developed by plants;

COLUMN A	COLUMN B
A. Thorns	i) It can be found on the stem and petioles of roses and are formed by the epidermis
B. Spines	ii) Found on a lemon tree (Citrus sp.) are modified branches, as can be seen by their position in the axil of a leaf
C. Prickles	iii) Found on shoot and leaves of tomato (Solanum lycopersicum) are derived from epidermal cells
D. Trichomes	iv) which are characteristic of cacti (Opuntia spp.) in the New World, are modified leaves

Match correctly following combination of barrier developed by plants ;

#Question id: 3267

#Section 3: Genetics, Cellular and Molecular Biology

In a typical Mendelian population, individuals carrying gene ‘a’ in homozygous condition suffer from phenylketonurea. Those with A in homozygous condition are normal. Others, who are heterozygotic with Aa, are carriers. If the frequency of ‘a’ in a population is 0.20, what is the percentage of normal individual in the population?

#Question id: 3268

#Section 3: Genetics, Cellular and Molecular Biology

A population of insects is in Hardy-Weinberg equilibrium for a gene with alleles A = orange and a = yellow eyes. There are 91% orange and 9% yellow individuals in the population. If the fitness of the yellow phenotype suddenly drops to zero, what will be the allele frequency in the next generation?

#Question id: 3269

#Section 3: Genetics, Cellular and Molecular Biology

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of

#Question id: 3270

#Section 3: Genetics, Cellular and Molecular Biology

Heterozygote advantage should be most closely linked to which of the following?

#Question id: 3271

#Section 3: Genetics, Cellular and Molecular Biology

Consider hemophilia A, a clotting disorder caused by an X-linked recessive allele with a frequency (q) of approximately 1 in 10,000. The frequency of the disease among females and among male respectively

#Question id: 3273

#Section 3: Genetics, Cellular and Molecular Biology

The number of forward mutations is equal to the number of reverse mutations then

a) Population is in equilibrium for forward and reverse mutation rates

b) The population is being in Hardy–Weinberg equilibrium

c) No further change in allelic frequency