BNNS502 pt 2 Exam Study Guide 2024

BNNS502 pt 2 Exam Study Guide 2024 Functions of the nucleus - Ans:-Control cellular structure, directs cellular activity, produces ribosomes How many pairs of chromosomes does the body have - Ans:-23 2 chromosomes making up a chromosome pair are called - Ans:-Homologous chromosomes Allelels are - Ans:-Alternative versions of a gene Describe Homozygous vs Heterozygous alleles - Ans:-Homozygous have identical info for a trait where as heterozygous have different What are the 2 types of cell division - Ans:-Somatic and reproductive What is the aim of somatic cell division - Ans:-Replace dead or injured cells or add new ones via mitosis and cytokinesis What s the aim of reproductive cell division - Ans:-Produce gamete haploid(23 single chromosomes) cells via meiosis What are the 3 stages of somatic cell division - Ans:-- Interphase -Mitosis -Cytokinesis ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 2/16 What does Interphase involve - Ans:-Doubling of genetic material, DNA unzips via enzyme presence What does Mitosis involve - Ans:-4 stages in which nucleus/chromosomes divide What occurs during cytokinesis - Ans:-Division of cytoplasm to create 2 identical daughter cells Describe meiosis I and meiosis II - Ans:-Meiosis I: 4 Stages that produce 2 genetically different cells Meiosis: Similar to mitosis (division of cytoplasm) What is the purpose of crossing over during meiosis I - Ans:-Genetic variation because of the exchange of genes homologous chromosomes What is cancer - Ans:-The result of uncontrolled or abnormal cell proliferation resulting in excess tissue called a tumour Carcinoma cancers arise from - Ans:-Epithelial tissue Leukaemia cancer arises from - Ans:-WBC Define inheritance - Ans:-Passage of hereditary traits from one generation to another Compare genotype to a phenotype - Ans:-Genotype is the genetic makeup of an individual and Phenotype is the physical characteristic determined by the genotype Define Mutation - Ans:-Permanent heritable change in a gene ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 3/16 Homozygous vs Heterozygous - Ans:-Homozygous: Same alleles (PP,pp) Heterozygous: Different alleles (Pp) Are genetic disorders Dominant or recessive - Ans:-Recessive and takes both parents to be carriers Autosomes vs sex chromosomes - Ans:-Autosomes: Any chromosome that isn't a sex chromosome Sex chromosome: 23rd pair (XX or XY) XX and XY code for - Ans:-XX: Female XY: Male What does the X chromosome contain - Ans:-Genes important for brain function, clottong factor and cone pigments Why are male sex linked traits more common - Ans:-Because it always expressed because there is no corresponding allele on Y chromosome, females must have 2 sexlinked recessive alleles What errors can occur during meiosis - Ans:-Trisomy (2n+1) or monosomy (2n -1) Down syndrome occurs when - Ans:-There is an extra 21st chromosome What is a teratogen - Ans:-Any agent or influence that causes developmental defects in the embryo ie chemicals, drugs, cigarettes, irradition ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 4/16 Name some autosomal dominant genetic disorders and what causes them - Ans:-Huntingtons disease, gene specific breast and ovarian cancers. Caused by mutation on a single gene Name some autosomal recessive genetic disorders and what causes them - Ans:-Cystic fibrosis, sickle cell disease. Caused my a mutation of 2 gene pairs on a chromosome Name an X-linked recessive disorder - Ans:-Haemophilia What is the function of the ovaries - Ans:-Produce oestrogen and progesterone, produce secondary oocyte and expel it into pelvic cavity. Name the structure of the ovaries and what they contain - Ans:-Ovarian cortex- ovarian follicle/oocyte Ovarian medulla-blood vessels, lymphatics & nerves What are the finger like processes at the start of the fallopian tube and what is there purpose - Ans:- Fimbriae- drape over ovary to create currents that carry oocyte into