The nervous system
Comprises the central nervous system (CNS: the brain and spinal cord) and the
peripheral nervous system (PNS, including spinal nerves and cranial nerves).
Messages are sent in both directions (between the muscles and the CNS) by cells
Hormone: a chemical substance produced in one location in the body and carried
through the blood stream to effect change on target cells.
Most are controlled by negative feedback mechanisms.
Hormones to know: insulin, glucagon, thyroxin, leptin,
Change the message of mRNA into protein.
The mRNA molecule that was made in the nucleus moves to the cytoplasm through a
Transcribing mRNA used the same language with nucleotides but now are translating
into a diff
Amino acid a certain name given to each codon (used in describing the protein sequence)
- specific grouping of three bases (triplet code)
-must be transcribed into RNA first
Base pairs occurs between a purine and pyrimidine, known as compl
Sexual Reproduction Part 2
undifferentiated germ cells (oogonia) divide mitotically until
the 5th month of gestation
Oogonia begin the 1st meiotic division but do not complete it
(Prophase I) primary oocytes (2n, diploid)
No further de
Childbirth and pregnancy
Summary: Comparing spermatogenesis and oogenesis
Compare spermatogenesis and oogenesis table in Pearson textbook
Oogenesis Fig 46.13 p. 924
Spermatozoa absorb some of the fructose in the semen.
Adaptions for productions and release of gametes
In females, adaptations for fertilization and embryonic development
The role of testosterone
Determines sex (testosterone level causes the development of male genita
Two main categories of mutations: chromosomal mutations and point mutations.
Without mutations, there can be no evolution!
Changes to a single base pair.
Homeostasis = same state
The human body acts to keep many variables within limits
These variables include:
o Blood pH
o Blood CO2 concentration
o Blood glucose concentration
o Body temperature
o Water balance within tissues
5.1: Communities and Ecosystems
Define species, habitat, population, community, ecosystem and ecology.
Distinguish between autotroph and heterotroph.
Distinguish between consumers, detritivores and saprotrophs.
Describe what is meant by a food cha
Plant Science Notes
Plant Structure and Growth
Land plants are divided into 3 major groups:
No conducting tissue
Small, growing close to the ground
Ecology and Conservation (Option G)
G1: Community Ecology
Outline the factors that affect the distribution of plant species including temperature, water, light, soil pH,
salinity, and mineral nutrients.
Explain the factors that affect the distribution of
1. Communities and Ecosystems
1. Define species, habitat, population, community, ecosystem, ecology and trophic level.
Species: a group of organisms that can interbreed and produce fertile offspring.
Habitat: the environment in which a species
Paper 1 Overview
Water is a good coolant because it takes a lot of energy to increase the temperature of water.
Galactose is a monosaccharide; lactose is a disaccharide.
The feather colour of a certain breed of chicken is controlled by codominant alleles.