Which one of the following denotes a 'true' fruit?
- A.When only the thalamus of the flower grows and develops into a fruit
- B.When only the receptacle of the flower develops into a fruit
- C.When fruit originates only from the calyx of a flower
- D.When only the ovary of the flower grows into a fruit
Correct answer
Explanation
The correct answer is D, When only the ovary of the flower grows into a fruit. A true fruit is a ripened ovary and nothing else.
After fertilisation, the ovary of a flower develops into the fruit, its wall becomes the pericarp and the ovules inside become seeds. When the whole fruit comes from the ovary alone, botanists call it a true fruit; mango, tomato, grape and coconut are examples. When other floral parts such as the thalamus also grow and form part of the fruit, it is called a false fruit or pseudocarp. Apple and pear are classic false fruits, where the fleshy edible part is the swollen thalamus, and the cashew 'apple' is the enlarged pedicel.
A and B describe growth of the thalamus or receptacle, which are two names for the same part, and this produces a false fruit such as the apple. C is wrong because the calyx is the outer whorl of sepals; it may persist on some fruits but never forms a fruit by itself.
Exam tip: true fruit = ovary only (mango); false fruit = ovary + thalamus (apple, pear).
Practice Questions
View allWhich of the following are nitrogen-fixing plants?
1. Alfalfa
2. Amaranth
3. Chickpea
4. Clover
5. Purslane (Kulfa)
6. Spinach
Select the correct answer using the code given below:
- A.1, 3 and 4 only
- B.1, 3, 5 and 6 only
- C.2, 4, 5 and 6 only
- D.1, 2, 4, 5 and 6
Show answer
Alfalfa, chickpea and clover are legumes, and legumes fix nitrogen. Plants of the legume family (Fabaceae) carry root nodules that house Rhizobium bacteria.
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- A.Alpha and Beta radiations only
- B.Alpha and Gamma radiations only
- C.Beta and Gamma radiations only
- D.Alpha, Beta and Gamma radiations
Show answer
Neither beta nor gamma emission changes the total number of protons and neutrons in a nucleus, so the mass number stays the same.
Read the full explanation →Which one among the following statements about facilitated transport in plants is correct?
- A.All passive transports are types of facilitated transport.
- B.Facilitated transport is an example of active transport.
- C.Water moves across plasma membrane by active transport.
- D.Facilitated transport requires assistance of carrier proteins.
Show answer
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Read the full explanation →Who among the following has coined the term 'Quark', the fundamental particles that make up protons and neutrons in an atomic nucleus ?
- A.Richard Feynman
- B.Murray Gell-Mann
- C.Albert Einstein
- D.Niels Bohr
Show answer
The American physicist Murray Gell-Mann proposed quarks in 1964 and gave them their name. Gell-Mann, and independently George Zweig, suggested that protons, neutrons and other such particles are built from smaller units.
Read the full explanation →The spindle fibre is attached to which of the following specific regions of the chromosomes?
- A.Kinetochore
- B.Chromonema
- C.Telomere
- D.Centriole
Show answer
Spindle fibres attach to the kinetochore, a disc-shaped protein structure on the centromere of each chromosome. During cell division the spindle, made of microtubules, pulls the copies of each chromosome apart.
Read the full explanation →