Life Sciences June Pre-Examination 1 Review

Comprehensive practice questions covering DNA, meiosis, genetics, human reproduction, and the nervous/endocrine systems based on the June 2023 Life Sciences Pre-Examination.

What is the process where one DNA molecule produces two identical DNA molecules?

Replication

When a cell divides by meiosis, what is the result?

Four haploid gametes

What event specifically characterizes metaphase I of meiosis?

Homologous chromosomes arrange themselves at the equator

In bird reproductive strategies, what is 'altricial development'?

A strategy where hatchlings are helpless and unable to move and feed themselves

What reproductive strategy involves the development of the young inside the uterus where it receives nutrients via the placenta?

Vivipary

Where are sperm cells in humans temporarily stored?

Epididymis

What is a primary function of the amniotic fluid?

To act as a shock absorber to protect the foetus

What are the possible genotypes for an individual with blood group A?

$I^{A}I^{A}$ or $I^{A}i$

Which hormone is responsible for controlling the metabolic rate?

Thyroxin

What biological term describes genetically identical organisms formed using biotechnology?

Cloning

What are the undifferentiated animal cells that can form any type of tissue called?

Stem cells

What is the point of crossing over between two adjacent chromosomes?

Chiasma

Which part of the brain connects the left and right hemispheres?

Corpus callosum

What is the function of the centromere during meiosis?

It holds the two chromatids together

What is the name of the process that occurs at the chiasma during Prophase I?

Crossing over

Which blood vessel transports deoxygenated blood from the foetus towards the placenta?

Umbilical artery

Which branch of the autonomic nervous system restores an increased heart rate back to normal?

Parasympathetic nervous system

What structure in the eye absorbs light to prevent internal reflection?

Choroid

Define 'karyotype' according to the biological terms.

The number, shape and arrangement of all the chromosomes in the nucleus of a somatic cell

What hormone stimulates ovulation in humans?

LH / Luteinizing hormone

Who were the first scientists to discover the double helix structure of DNA?

Watson and Crick

In a human karyotype, how many autosomes are typically present?

$$44$$

What is the name for the type of gametogenesis that takes place in the male reproductive system?

Spermatogenesis

Identify the site of fertilisation in the female reproductive system.

Fallopian tube / oviduct

Which part of the ear absorbs excess pressure waves from the inner ear?

Round window

What condition is caused by the progressive degradation of the myelin sheath?

Multiple Sclerosis

State Mendel's principle of segregation.

The pair of alleles on homologous chromosomes separate during meiosis so that only one allele of each pair is present in the gamete

During eye accommodation for a distant object, what happens to the ciliary muscles and the lens?

Ciliary muscles relax and the lens becomes less convex / flattened

How many chromosomes are present in a human sperm cell or ovum?

$$23$$