1What is the reproductive success of an individual determined by?
The ability to produce fertile offspring that survive and reproduce offspring of their own.
2What is the main difference between asexual and sexual reproduction?
Asexual involves one parent and identical offspring, while sexual involves two parents and genetically unique offspring.
3Why does external fertilisation usually occur in aquatic environments?
To prevent the dehydration of gametes.
4What are the four main stages of a sexually reproducing plant's life cycle?
Pollination, fertilisation, seed dispersal, and germination.
5What is vegetative propagation?
When new individuals arise from portions of the root, stem, leaves, or buds and are clones of the parent.
6How do fungi reproduce asexually?
Through budding or the dispersal of spores.
7Which gland is responsible for the release of most hormones involved in reproduction?
The pituitary gland.
8What are the roles of FSH and LH in the ovarian cycle?
They are involved in the maturation of ova through follicle development and the release of the egg.
9What is the function of oxytocin in reproduction?
It is involved in foetal development and stimulating uterine contractions.
10How does Artificial Insemination (AI) benefit agriculture?
It allows elite male genetics to be spread worldwide quickly and cheaply.
11What are the three components of a DNA nucleotide?
A sugar, a phosphate, and a nitrogenous base.
12How does RNA differ from DNA in terms of nitrogenous bases?
RNA contains Uracil (U) instead of Thymine (T).
13What is the role of helicase in DNA replication?
It unwinds the DNA double helix and unzips the strands by breaking hydrogen bonds.
14Define the term "semi-conservative" in DNA replication?
The resulting DNA molecules contain one original strand and one newly synthesised strand.
15What is the primary role of mitosis?
Growth, repair, and replacement of cells in multicellular organisms.
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16What occurs during "crossing over" in meiosis?
Genes switch between homologous chromatids to create genetic variation.
17What is a polypeptide?
A chain of amino acids held together by peptide bonds.
18Where does transcription occur in a eukaryotic cell?
In the nucleus.
19What happens during the "splicing" of pre-mRNA?
Introns (non-coding regions) are removed and exons (coding regions) are joined together.
20What is the function of tRNA in translation?
It carries specific amino acids to the ribosome and matches its anticodon to the mRNA codon.
21Define the difference between genotype and phenotype?
Genotype is the genetic make-up; phenotype is the physical appearance or observable traits.
22What is the quaternary structure of a protein?
The arrangement formed by the interaction of two or more polypeptide chains.
23What is a germline mutation?
A mutation occurring in sex cells that can be passed on to offspring.
24What is the difference between codominance and incomplete dominance?
In codominance both alleles are expressed; in incomplete dominance, the traits blend into a third phenotype.
25Why do recessive sex-linked traits appear more frequently in males?
Males only have one X chromosome, so a single recessive allele on that chromosome will be expressed.
26What are the three main steps of PCR?
Denaturation (heating), Annealing (cooling for primers), and Extension (synthesising DNA).
27How does gel electrophoresis separate DNA fragments?
By size, using an electric current to pull negatively charged DNA towards a positive electrode.
28What are Short Tandem Repeats (STRs)?
Sections of non-coding DNA that repeat many times and are unique to individuals, used in DNA profiling.