Biology 30 Review

Unit A

Main goals: Examine how the nervous and endocrine systems contributes to homeostasis

1. Nervous System

• Structure of the Neuron

• Action potentials, neurotransmitters, and the synapse

• Reflex Arc

• Peripheral Nervous System vs Central Nervous System

• Structure of the Brain (CNS)

• Structure of the Spinal Cord (CNS)

• Peripheral Nervous System structure

• Anatomy of the eye

• Anatomy of the ear

2. Endocrine System

• Endocrine glands

• Function of hormones and negative feedback loops

• Relationship between the endocrine and nervous system

• Effects of hormone imbalances

Unit B

Main goals: Investigating the human reproductive system and its role in reproduction

1. Structures and functions

• Female Reproductive System:

• Male Reproductive System:

• Sperm

• Ovum

2. Hormones

• What is the main purpose of progesterone?

The main function of progesterone is to prepare the endometrium (lining of your uterus) for a fertilized egg to implant and grow. Estrogen is a steroid hormone associated with the female reproductive organs and is responsible for developing female sexual characteristics.

• What is the main purpose of FSH?

In women, FSH helps manage the menstrual cycle and stimulates the ovaries to produce eggs. FSH helps control the menstrual cycle. It also triggers the release of an egg from the ovary.

• What is the main purpose of Testosterone?

Testosterone is a sex hormone that plays important roles in the body. In men, it's thought to regulate sex drive (libido), bone mass, fat distribution, muscle mass and strength, and the production of red blood cells and sperm.

• How do BCPs work?

Birth control pills (BCPs) contain man-made forms of 2 hormones called estrogen and progestin. Either of these hormones can be synthetically made and used in contraceptives. Higher than normal levels of estrogen and progestin stop the ovary from releasing an egg.

• The Menstrual Cycle

3. Pregnancy

• Corpus Luteum:

The primary function of the corpus luteum is secretion of progesterone for maintenance of pregnancy.

• Human fetal development

• Implantation

The attachment of the fertilized egg or blastocyst to the wall of the uterus at the start of pregnancy,

• Germ Layers

The three germ layers are the endoderm, the ectoderm, and the mesoderm. The ectoderm gives rise to the skin and the nervous system. The mesoderm specifies the development of several cell types such as bone, muscle, and connective tissue. Cells in the endoderm layer become the linings of the digestive and respiratory system, and form organs such as the liver and pancreas.

• The Placenta

The placenta is an organ that develops in the uterus during pregnancy. This structure provides oxygen and nutrients to a growing baby. It also removes waste products from the baby's blood. Chorion + Amnion (fetus)

• Labour

• Lactation

Unit C

1. Meiosis and Mitosis

Key Skill: Describe the processes of mitosis and meiosis

Key Concept: The different processes of cell division

• Defining chromosome number in somatic and sex cells using ploidy

Watch the following video: Diploid Cell vs Haploid Cell Video

Answer the following questions:

• what does ploidy mean

the number of sets of chromosomes in a cell, set = n

• how do we count ploidy

Humans are diploid organisms, normally carrying two complete sets of chromosomes in their somatic cells: one copy of paternal and maternal chromosomes, respectively, in each of the 23 homologous pairs of chromosomes that humans normally have. Number of chromosomes = number of centromeres, chromatids vs chromosomes.

• what is the difference between diploid and haploid?

Haploid cells contain only one set of Chromosomes (n). Diploid, as the name indicates, contains two sets of chromosomes (2n).

• define chromosome number in somatic cells and compare them to gametes

Gametes = haploid, somatic = diploid

2. Events of the cell cycle

• Meiosis

Meiosis is cell division that takes place in the gonads, producing gametes. It is important for genetic diversity due to the crossing over in prophase 1.

• Mitosis

• Growth - body cells

• Gametogenesis:

Oogenesis produces 4 spermatozoa, Oogenesis produces 1 mature ovum and 3 polar bodies.

• Differences between Meiosis and Mitosis

Meiosis goes through two rounds and has crossing over. Meiosis creates 4 non-identical daughter cells.

• Processes of crossing over

Crossing over refers to the exchange of genetic material or chromosome segments between non-sister chromatids in meiosis. This genetic process occurs between homologous regions of matching chromosomes and the interchange of homologous chromosomes. Crossing over produces a new combination of genes. It happens to produce a new combination of genes - genetic diversity.

3. Classical Genetics

Key Skill: Describe the processes of mitosis and meiosis

Key Concept: The different processes of cell division

Mendel’s laws

1. Law of Dominance

Hybrid offspring (heterozygous) will only inherit the dominant trait in the phenotype. The alleles that are suppressed are called the recessive traits while the alleles that determine the trait are known as the dominant traits.

2. Law of Segregation

During the production of gametes, two copies of each hereditary factor segregate so that offspring acquire one factor from each parent. In other words, allele (alternative form of the gene) pairs segregate during the formation of gamete and re-unite randomly during fertilization.

3. Law of Independent Assortment

A pair of traits segregates independently of another pair during gamete formation.

Genotypes and Phenotypes

Allele vs Gene: allele (alternative form of the gene)

Dominant/Recessive: An allele of a gene is said to be dominant when it effectively overrules the other (recessive) allele.

Genotype vs Phenotype: A person's genotype is their unique sequence of DNA. More specifically, this term is used to refer to the two forms a person has inherited from their mother and father, for a particular gene. Phenotype is the observable expression of this genotype – a person's presentation.

• Multiple:

• Incomplete:

• Co-dominant:

Influence of linkage and crossing over

During linkage, the genes on the homologous chromosome are inherited together but crossing over separates two genes in a chromosome and segregates them into two gametes.

What is the relationship between variability and the number of genes controlling a trait?

More genes = more variability

Sex-linked inheritance compared to autosomal as invested by Morgan

Autosomes are all the chromosomes except the X or Y chromosome, and they do not differ between males and females, so autosomal traits are inherited in the same way regardless of the sex of the parent or offspring. Traits controlled by genes on the sex chromosomes are called sex-linked traits.

4. Molecular Genetics

Key Skill: Describe the processes of mitosis and meiosis

Key Concept: The different processes of cell division

Historical events that led to DNA

1. 1866 - Gregor Mendel discovers the basic principles of genetics

2. 1869 - Friedrich Miescher identifies "nuclein" (dna)

3. 1952 - Rosalind Franklin photographs crystallized DNA fibres

4. 1953 - James Watson and Francis Crick discover the double helix structure of DNA

Structure of DNA

DNA is made of two linked strands that wind around each other to resemble a twisted ladder — a shape known as a double helix. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups. Attached to each sugar is one of four bases: adenine (A), cytosine (C), guanine (G) or thymine (T).

How is genetic information stored?

Genetic information is carried in the linear sequence of nucleotides in DNA. Each molecule of DNA is a double helix formed from two complementary strands of nucleotides held together by hydrogen bonds between G-C and A-T base pairs.

• DNA replication steps

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• Transcription and translation

Effects of mutation

• new genes

• DNA is in mitochondria, chloroplasts and nucleus, considering that how are organisms related to each other?

• Dna is a universal language