Reproduction Methods
What is the main advantage of asexual reproduction?
Fast reproduction without needing a mate.
What process describes the joining of a sperm and an egg?
Fertilisation.
What is the purpose of mitosis?
Growth, repair, and producing genetically identical cells.
What does mRNA stand for?
Messenger RNA.
What does a Punnett square show?
The possible genotypes of offspring.
Which organism reproduces by binary fission: fungi, bacteria, or animals?
Bacteria.
Where does implantation occur in mammals?
The uterus lining (endometrium).
Name the complementary base pairs in DNA vs. RNA
A–T and C–G.
A-U and C-G
Where in the cell does transcription occur?
Nucleus.
What is a genotype?
The genetic makeup of an organism (allele combination).
Name one advantage of internal fertilisation over external fertilisation.
Increased survival of gametes / protection inside the body.
Which hormone maintains the uterus lining during early pregnancy?
Progesterone.
Identify one main difference between mitosis and meiosis.
Meiosis produces haploid gametes and increases variation; mitosis produces identical diploid cells.
What is the role of tRNA?
Delivers amino acids to the ribosome during translation.
What is the purpose of meiosis in reproduction?
Produces gametes and increases genetic variation.
Name the type of reproduction used by fungi that involves producing microscopic cells that can disperse widely.
Spores.
What is the main role of hCG during early pregnancy?
It maintains the corpus luteum so it continues producing progesterone to support the uterus lining.
Why is DNA replication essential for continuity of species?
It ensures genetic information is accurately passed to new cells/gametes.
State the difference between transcription and translation.
Transcription makes mRNA from DNA; translation uses mRNA to build a polypeptide.
Draw conclusions from this pedigree: If a trait appears in every generation, is it likely dominant or recessive?
Dominant.
Protists can reproduce asexually by binary fission and budding. Describe one difference between these two processes.
Budding forms a smaller daughter cell that grows off the parent; binary fission splits roughly equally into two identical cells.
Explain how oestrogen and progesterone work together to prepare and maintain the uterus for pregnancy.
Oestrogen builds the lining of the endometrium and builds more blood vessels in the endometrium, while progesterone stabilises and maintains it to support implantation and early embryonic development.
Describe how crossing over in meiosis leads to new combinations of alleles.
Homologous chromosomes exchange segments, producing recombinant chromatids with new allele combinations.
Explain how both genes and the environment can affect phenotype.
Genes provide instructions for proteins, but environmental factors (e.g., nutrition, temperature) influence how or when these genes are expressed.
A heterozygous Aa parent is crossed with an aa parent. What are the genotype ratios?
1:1