Unit 2 : Humans - Their origins and their adaptions 0.0 / 5 ? Human BiologyUnit 2ASAQA Created by: NatashaLittlewood0810Created on: 27-05-14 21:26 42978351106 Across 1. Not cancerous. Grow slowly, often covered in fibrous tissue that stops cells invading other tissues. Often harmless, but can cause blockages + put pressure on organs, some end up malignant. (6, 7) 6. 2.5-1.5 million years ago. Same size as Australopithecus but had a larger brain and less protruding jaw. (4, 7) 8. Increases cell number in growth and repair tissue. The cell divides to produce 2 new cells, each containing an exact copy of DNA from parent cell. All cells made in body contain same alleles as we grow from zygote-single fertilised cell. 'Asexual' (7) 9. Similarities in early stages of an organisms development. (13) Down 2. Amount of O2 needed to get rid of toxic Lactate produced during exercise. Some broken down in the muscles, some carried in the liver and changed to glucose and stored as glycogen. (6, 4) 3. Cells DNA unravels and replicates to double its genetic content. Organelles also replicate so it has spare ones, and its ATP content is increased to provide energy for cell division. (10) 4. O2 carried round body in red blood cells by protein-H. O2 joins to H in lungs to form oxyhaemoglobin. (11) 5. Sections of DNA that contain coded information that determines the nature and development of organisms. (5) 7. Proteins whose synthesis is controlled by DNA. They control metabolic pathways and thus influence the phenotype of an organism. (7) 10. Chromosomes condense. Bundles of protein 'centrioles' start moving to opposite ends of the cell, forming a network of protein fibres across the spindle. The nuclear envelope breaks down and chromosomes lie free in the cytoplasm. (8)
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