Multiple Choice Pt.2 Flashcards
(27 cards)
Darwin’s theory of natural selection mechanisms
Variation, Inheritance, Selection, Time and Adaptation.
Natural Selection
characteristics of a population change over many generations, heritable traits & reproduce passing their traits to offspring.
Homologous structures -what are they
Structures that have similar structural elements and origin but may have a different function
Types of selection
Stabilizing
favours intermediate phenotypes and acts against extreme variants.
Types of selection: Directional
favours the phenotypes at one extreme over another, resulting in the distribution curve of phenotypes shifting in the direction of that extreme
Types of selection: Disruptive (diversifying):
favours the extremes of a range of phenotypes; can result in the elimination of intermediate phenotypes
What are proteins made out of?
Amino acids joined by peptide bonds forming chains
Nutrients in food are broken down why?
- To provide energy,
- regulate cellular activities
- build and repair tissues
Why do we need fiber in our diets
helps regulate the body’s use of sugars, helping to keep hunger and blood sugar in check.
Why do we need oxygen
helps organisms grow, reproduce, and turn food into energy.
Capillaries -what, where
A tiny blood vessel that carries blood from the arteries to the veins; site of gas, nutrient, and waste exchange
Found in the vascular system
Movement of diaphragm
Diaphragm: a sheet of muscle that separates the thoracic cavity from the abdominal cavity
Control air pressure inside the lungs
Changes in air pressure cause air to move in and out of the lungs
movement of air in lungs
Inhalation: rib cage moves up and out, diaphragm contracts and moves down, pressure in lungs decreases and air comes rushing in
Exhalation: rib cage moves down and in, diaphragm relaxes and moves up, pressure in lungs increases and air is pushed out
Structure of the Trachea
Trachea: the tube that carries air from the nasal passages or month to the bronchi and then to the lungs; also known as the windpipe
Other functions of the blood
transporting materials in the body and regulating the concentration of substances and heat in the body
How blood moves through veins
Contraction of muscles and one-way valves
Why is photosynthesis important
It is the source of energy and food for all organisms.
It releases oxygen into the environment which is utilised by organisms.
Root tip/cap
A protective covering at the tip of the root
Consists of parenchyma cells and reduces friction as root grows
Vascular
To transport water and dissolved substances throughout the plant
Vascular tissue
Xylem
carries water and minerals from the roots to the rest of the plant
Consists of dead tube-shaped cells with lignin
Vascular tissue
Phloem
used for transporting larger molecules including sugars
Consists of living cells in tubular form
Stomata
A small opening, usually in the leaf, that allows gas exchange
Dicot image
a major cluster of flowering plants that have two cotyledons; a plant embryo has two cotyledons
Monocot
major cluster of flowering plants that have one cotyledon; a plant embryo with one cotyledon
