Reproduction SME flashcards
Mocks
Define the term sexual reproduction.
Sexual reproduction is the reproductive process during which the nuclei of two gametes fuse to form a zygote and genetically different offspring are produced.
Define the term fertilisation
Fertilisation is the fusion of gamete nuclei.
What are gametes?
Front
Sexual & Asexual Reproduction: Differences
What are gametes?
Back
Sexual & Asexual Reproduction: Differences
How many chromosomes do human gametes contain?
Human gametes contain 23 chromosomes, half of the normal 46 found in other body cells because they only contain one copy of each chromosome.
Define the term asexual reproduction.
Asexual reproduction is the reproductive process that results in genetically identical offspring from one parent.
How do offspring produced by asexual reproduction compare to their parent and each other?
Offspring produced by asexual reproduction are genetically identical to the parent and to each other, as there is no fusion of gametes and no mixing of genetic information, resulting in clones.
What are the advantages of sexual reproduction?
Sexual reproduction allows for genetic variation among offspring, which can increase the chances of survival in changing environments and help in evolution.
What are the disadvantages of sexual reproduction?
Sexual reproduction requires the production of specialised gametes and the search for a mate, which can be energetically costly and time-consuming.
What are the advantages of asexual reproduction?
Asexual reproduction is efficient in rapidly producing numerous offspring, requires only one parent, and ensures the preservation of favourable traits.
What are the disadvantages of asexual reproduction?
Asexual reproduction lacks genetic variation, making offspring vulnerable to changes in the environment. It may also lead to the accumulation of harmful mutations and limit adaptability to new conditions.
How does the number of parents differ in sexual and asexual reproduction?
Sexual reproduction involves two parents while asexual reproduction involves one parent.
What type of cell division is required for sexual reproduction?
Meiosis is required for sexual reproduction.
Define fertilisation.
Fertilisation is the fusion of gamete nuclei, resulting in the formation of a zygote.
What is the process of fertilisation in humans?
Fertilisation in humans involves the fusion of a sperm cell with an egg cell.
What is the result of fertilisation?
The result of fertilisation is the formation of a zygote/fertilised egg cell.
True or False?
Fertilisation leads to variation in offspring.
True.
Fertilisation leads to variation in offspring.
Define zygote.
A zygote is a fertilised egg cell formed by the fusion of gamete nuclei.
What is the significance of variation in offspring?
Variation in offspring allows for adaptation to changing environments.
What is the main source of genetic variation in offspring in sexual reproduction?
The main source of genetic variation in offspring in sexual reproduction is the production of gametes by meiosis, resulting in new combinations of alleles on the chromosomes.
State the importance of fertilisation.
Fertilisation is important as it leads to the formation of genetically diverse offspring.
True or False?
Fertilisation involves the fusion of gametes from the same parent.
True or False?
Fertilisation involves the fusion of gametes from the same parent.
Define embryo.
An embryo is the early developmental stage of a multicellular organism that is produced after cell division of a zygote.
Define the term pollination.
Pollination is the process of transferring pollen from the anther (male part) to the stigma (female part) of a flower.
What are the two main mechanisms of pollination?
The two main mechanisms of pollination are insect pollination and wind pollination.
True or False?
Pollen is capable of locomotion.
False.
Pollen is not capable of locomotion. It requires a mechanism such as wind, water or insects to transfer it from place to place.
Describe how insect-pollinated flowers are adapted for pollination.
Insect-pollinated flowers have structures that allow insects to transfer pollen, such as sticky pollen and nectar-producing glands. They attract insects using brightly coloured petals and attractive smells.
Describe how wind-pollinated flowers are adapted for pollination.
Wind-pollinated flowers produce large amounts of lightweight pollen and have exposed stigmas to catch the pollen carried by the wind.
What is cross-pollination?
Cross-pollination occurs when pollen is transferred from the anther of a flower to the stigma of a flower from another plant of the same species.
What is self-pollination?
Self-pollination occurs when pollen is transferred from the anther of a flower to:
the stigma of the same flower
the stigma of another flower on the same plant
What is the importance of pollination in plant reproduction?
Pollination is crucial for plant reproduction as it facilitates the transfer of pollen, leading to fertilisation and the production of seeds and fruits.
True or False?
Petals of insect-pollinated flowers tend to be brightly coloured.
True.
Petals of insect-pollinated flowers tend to be brightly coloured to attract pollinator insects.
How are anthers adapted in wind-pollinated plants?
Anthers are adapted in wind-pollinated plants by swinging on long filaments outside of the flower to transfer pollen to the wind.
Define fertilisation in plants.
Fertilisation is the process in which the nucleus of a male pollen grain fuses with the nucleus of an ovum in the ovary, leading to the formation of a zygote.
How does fertilisation occur in plants?
Fertilisation in plants occurs when the pollen grain nucleus fuses with the ovum nucleus, typically in the ovary.
Describe the growth of the pollen tube in plants.
The pollen tube grows from the pollen grain towards the ovary, allowing the pollen nucleus to reach the ovum for fertilisation.
True or False?
The ovule contains the male gamete.
False.
The ovule contains the ovum, which is the female gamete.
What happens after fertilisation in plants?
After fertilisation, the ovule develops into the seed, while the ovary forms the fruit.
Why is fertilisation in plants important?
Fertilisation is essential for plant reproduction as it leads to the formation of a zygote, which develops into an embryo plant within the seed.
True or False?
Fertilisation occurs when the male and female gametes fuse.
True.
Fertilisation occurs when the nucleus of a male pollen grain fuses with the nucleus of the ovum (gametes) in the ovary.
What does the zygote develop into after fertilisation?
After fertilisation, the zygote develops into an embryo plant.
Define ovule.
An ovule is a structure within the ovary of a flower that contains the ovum, which is the female gamete.